Also from Latin, again stolen from Greek: our- or ouro-, from oura, meaning tail.

Ur- is also a prefix meaning original, primitive, or prototypical. The 'original version of' something. This is oft used today to create new words; Ur-feminist, Ur-grue, Ur-element, Ur-Hamlet. It may be hyphenated or separated from the word it is referring to by a space. It is often capitalized as a proper noun.

From the Greek ir- or ur-, meaning abide. It comes to us by way of German, probably first entering English in the word Ursprache (referring to a hypothetical 'first speech', the first language ever spoken by mankind).